/*
 * Alloy Analyzer
 * Copyright (c) 2002 Massachusetts Institute of Technology
 *
 * The Alloy Analyzer is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * The Alloy Analyzer is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with the Alloy Analyzer; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */

package alloy.symm;

import alloy.transl.ExprTransl;

/**
 * One tuple of a particular relation.  Normally, one Boolean variable
 * would be allocated to each tuple.  This class represents one tuple,
 * and {@link SymmetryBreaker} defines a fixed order of tuples by
 * constructing a fixed list of {@link Tuple}s, and defines Crawford's
 * lex-leader predicate for that order (i.e. a symmetry-breaking predicate
 * true of the smallest instance when instances are read as binary
 * numbers according to that order).
 */
class Tuple {
    /**
     * Translation of the relation from which this tuple is taken.
     * Since only one {@link ExprTransl} object is generated for each
     * relation during translation, we can just represent relations
     * by their translations, which is what we do here.
     */
    ExprTransl relTransl;

    /** Coordinates of the tuple within the relation. */
    int[] tupleIdx;
}
